Class 9 Physical Education Khel Praveen Unit 2 Science and Sports Solutions (NCERT 2026–27)

Q: What chapters are in Class 9 Khel Praveen Unit 2?

Unit 2, Science and Sports, contains four chapters: Chapter 5 Understanding Our Body, Chapter 6 Cardiorespiratory System, Chapter 7 Growth, Development, and Maturation, and Chapter 8 First Aid.

Q: What is the difference between growth, development and maturation?

Growth is a quantitative increase in body size that stops after maturity; development is the qualitative improvement of skills, function and behaviour that continues throughout life; maturation is the body's progression towards adulthood and full functional capacity, with different systems maturing at different times.

Q: What does PRICE stand for in first aid?

PRICE stands for Protection, Rest, Ice, Compression and Elevation. It improves on the basic R.I.C.E. method by adding Protection first, and is used for soft-tissue injuries such as a twisted ankle.

These Class 9 Physical Education Khel Praveen Unit 2 solutions cover Science and Sports from the new NCF-2023 Physical Education and Well-being textbook (2026–27). Unit 2 explores the scientific working of the human body during movement — bones, muscles and joints (Ch 5), the cardiorespiratory system (Ch 6), growth, development and maturation (Ch 7) and first aid (Ch 8) — with complete chapter notes, key terms and exam-ready answers to every textbook exercise.

Class: 9 Subject: Physical Education & Well-being Book: Khel Praveen Unit: 2 — Science and Sports Chapters: 5 Understanding Our Body, 6 Cardiorespiratory System, 7 Growth, Development, and Maturation, 8 First Aid Session: 2026–27

On this page

Unit overview
Chapter 5 — Understanding Our Body
Chapter 6 — Cardiorespiratory System
Chapter 7 — Growth, Development, and Maturation
Chapter 8 — First Aid
Key terms
Textbook exercise solutions
Extra practice questions
MCQs & Assertion–Reason
FAQs

Unit 2 Science and Sports – Overview

Unit 2, Science and Sports, looks at the human body as a living machine for movement. It begins with anatomy (the “what” and “where” of body parts) and physiology (the “how” and “why” they work), introducing bones, cartilage, tendons, ligaments, joints and the three muscle types, and how forces, levers and ranges of motion produce skilled action like kicking a ball. It then studies the cardiorespiratory system — breathing, cellular respiration, the heart, double circulation and the immediate and long-term effects of exercise. Next it distinguishes growth, development and maturation and the factors that shape them, explaining why classmates of the same age differ. Finally it teaches practical first aid — the PRICE/PEACE&LOVE principles, the three Ps, golden rules, BLS and CPR (DRSABCD), nosebleed care and safe transfer techniques — connecting science with everyday safety on the playground.

Chapter 5 — Understanding Our Body

This chapter studies the structures that make movement possible. Human anatomy is the study of the structure of the body (what parts are and where they are), while physiology explains how organs and systems function to maintain life. India’s ancient contribution is honoured through Maharṣhi Suśhruta, the ‘Father of Surgery’, whose Ayurvedic work influenced medicine worldwide.

Connective tissues of movement

Bone — a strong, rigid connective tissue forming the skeleton; it is active and constantly repairs itself.
Cartilage — tough yet flexible tissue that cushions bones and joints and reduces friction.
Tendon — a flexible band attaching muscle to bone (e.g. the Achilles tendon), absorbing impact.
Ligament — fibrous bands linking bone to bone, stabilising joints and limiting harmful movement.

Types of bones

Type of bone	Features	Examples
Long bones	Tubular, long axis, two articulating ends	Humerus, Femur
Flat bones	Flat and thin, possibly curved, protect organs	Cranial bones, Scapula
Irregular bones	Complex shapes	Vertebrae
Sesamoid bones	Lie within tendons	Patella, Scaphoid
Short bones	Cuboidal in shape	Carpal bones

Joints

A joint (articulation) is where two or more bones meet to allow movement and provide support. Joints are classified two ways. Structurally: fibrous (e.g. skull, no movement), cartilaginous (e.g. vertebrae, limited movement) and synovial (e.g. knee, freely movable). Functionally: immoveable (skull), slightly moveable (spine) and freely moveable (shoulder, hip, knee, elbow, wrist). Synovial joints are further classified into ball-and-socket, hinge, pivot, gliding, saddle and condyloid joints.

Muscles and movement

Muscles produce movement, maintain posture and circulate blood by contracting. The three types are skeletal (voluntary, striated, attached to bones), smooth (involuntary, non-striated, in hollow organs) and cardiac (only in the heart wall/myocardium, branched and self-stimulating). Movement is shaped by complexity of form, degrees of freedom and joint type. Force is the push or pull muscles create, strength is the force a muscle can produce against resistance, and power is strength combined with speed (explosive strength). Muscle actions include isometric, isotonic, concentric, eccentric and isokinetic contractions.

Chapter 6 — Cardiorespiratory System

Breathing (ventilation) is the physical act of inhaling oxygen and exhaling carbon dioxide using the lungs, chest muscles and diaphragm. Respiration happens at the cellular level: inside the mitochondria, oxygen breaks down glucose to release energy as ATP, producing carbon dioxide and water as waste. During inspiration the diaphragm contracts and moves down; during expiration it relaxes. Gas exchange occurs as external respiration (in the lung alveoli) and internal respiration (in body tissues).

Heart and circulation

The heart works like two pumps; each side has an atrium and a ventricle. Humans have a double circulatory system: pulmonary circulation sends oxygen-deficient blood from the right heart to the lungs, and systemic circulation sends oxygen-rich blood from the left heart to the body. Blood vessels in order are arteries → arterioles → capillaries (exchange) → venules → veins. The heart’s ‘lub-dub’ sound comes from valves closing: Lub (S1) = mitral and tricuspid valves; Dub (S2) = aortic and pulmonary valves. Blood pressure has systolic (heart contracts) and diastolic (heart relaxes) values.

Table 1: Effects of exercise on different parts of the body

Body Parts	Immediate Effect	Long-term Effect
Heart	Beats faster, pumps more blood	Larger, stronger, more efficient
Lungs	Breathing rate and depth increase	Greater capacity and efficiency
Muscles	Use more oxygen, contract more often	Increase in size, strength, and endurance
Blood Vessels	Redirect blood to the muscles	More capillaries, better circulation
Skin	More blood flow for cooling	Improved temperature regulation
Bones and Joints	No major immediate change	Stronger bones, better joint stability

Table 2: Key body changes at rest and during exercise

Key Body Changes	At Rest	During Exercise	Explanation
Blood Flow to Muscles	Low	Much higher (15–25 times increase)	Muscles need more oxygen and nutrients
Heart Rate	~70 beats/min	2–3 times faster	To pump blood more quickly
Muscle Activity	Low	High	Muscle fibres contract more often and require more energy
Muscle Temperature	Normal	Higher	Heat helps muscles contract more efficiently
Cardiac Output	~5 L/min	Up to 30 L/min	To send more blood to active tissues
Blood Flow to Stomach and Intestines	Normal	Lower	Blood is redirected to muscles
Blood Flow to Skin	Low	Higher	To release heat from the body
Oxygen Use	Low	Much higher	For energy production in muscles
Waste Removal	Low	Higher	To remove carbon dioxide and lactic acid

Chapter 7 — Growth, Development, and Maturation

Growth is the change in the size or composition of the body or a body part (quantitative, measurable, stops after maturity). Development is broader — behavioural and biological — such as motor skills, teamwork and emotional control, and continues throughout life. Maturation is the progression of the body towards adulthood; different systems mature at different times (for example, the skeletal system matures later than the reproductive system).

Aspect	Growth	Development	Maturation
Nature of change	Quantitative (size/weight)	Qualitative (function, skills, behaviour)	Qualitative and biological (timing of body-system changes)
Continuity	Stops after maturity	Throughout life	Until full maturity of systems
Example	Increase in height and weight	Learning to walk, read or play sports	Onset of puberty, closure of growth plates

Factors influencing these processes include genetics/heredity, nutrition, hormones, physical activity, health and medical care, environment, psychological/emotional support, socio-economic status and cultural lifestyle. The chapter clarifies terms like children (<12 years), adolescence (begins at puberty), youth (<19 years) and young athletes, and notes that improved sports performance may come from natural growth spurts, not only training. Growth plates (physes) are cartilage areas near bone ends that harden after puberty; the Tanner–Whitehouse 3 (TW3) method uses an X-ray of the left hand and wrist to assess skeletal maturity.

Chapter 8 — First Aid

Not all injuries bleed; soft-tissue injuries to muscles, tendons or ligaments cause pain, swelling and bruising without an open wound. For the first few hours, the R.I.C.E. principle is used.

Aspect	Action	Purpose or benefit
R – Rest	Stop playing or putting pressure on the injured part.	Prevents further tissue damage and starts healing.
I – Ice	Apply ice for 10–15 minutes every 2 hours.	Reduces pain and swelling. Always wrap ice in a cloth.
C – Compression	Wrap with an elastic bandage.	Limits swelling and provides support.
E – Elevation	Keep the injured limb raised above heart level.	Helps fluid drain away and reduces swelling.

PRICE adds Protection before R.I.C.E.; newer recovery methods are PEACE (Protection, Elevation, Avoid anti-inflammatories, Compression, Education) and LOVE (Load, Optimism, Vascularisation, Exercise). First Aid is the immediate care given before medical help arrives. Its aims are the Three Ps: Preserve Life, Prevent Worsening, Promote Recovery. The chapter also covers the seven golden rules (stay calm, ensure safety, call 112 early, give correct first aid, handle with care, use what you have, stay with the person), Basic Life Support (BLS) and CPR using the DRSABCD action plan (Danger, Response, Send for help, Airway, Breathing, CPR 30:2, Defibrillator), nosebleed management and safe transfer techniques.

CPR depths and technique (DRSABCD)

	Adult (>8 years)	Child (>1 year)	Infant (<1 year)
Pressure	2 hands	1 or 2 hands	2 fingers
Depth	5+ cm	5 cm	4 cm
Rate	Almost 2 compressions per second (100–120/min)
Breath	2 full breaths with head tilt and chin lift	2 shallow breaths with head tilt and chin lift	2 puffs with no head tilt and slight chin lift

Key Terms

Term	Meaning
Anatomy	The scientific study of the structure of the human body — what parts are and where they are.
Physiology	The study of how the organs and systems of the body function to maintain life.
Cartilage	Tough, flexible connective tissue that cushions bones and joints and reduces friction.
Tendon	A flexible band of tissue that attaches muscle to bone (e.g. the Achilles tendon).
Ligament	A fibrous band that links bone to bone and stabilises joints.
Synovial joint	A freely movable joint with a fluid-filled cavity (e.g. knee, shoulder).
Skeletal muscle	Voluntary, striated muscle attached to bones that produces movement and posture.
Power	Strength combined with speed; also called explosive strength.
Ventilation	The physical act of breathing — inhaling oxygen and exhaling carbon dioxide.
Cellular respiration	The process in cells where oxygen breaks down glucose to release energy as ATP.
Double circulation	System in which blood passes through the heart twice in one full circuit of the body.
Cardiac output	The amount of blood the heart pumps into the aorta each minute (about 5 L/min at rest).
Maturation	The progression of the body towards adulthood and full functional capacity.
Growth plate (physis)	Cartilage near the ends of long bones where new bone is added until it closes after puberty.
RICE / PRICE	First-aid principle for soft-tissue injuries: (Protection,) Rest, Ice, Compression, Elevation.
Three Ps of First Aid	Preserve Life, Prevent Worsening, Promote Recovery.
BLS	Basic Life Support — immediate help (including CPR) when breathing or heartbeat stops.
DRSABCD	The BLS action plan: Danger, Response, Send for help, Airway, Breathing, CPR, Defibrillator.

Textbook Exercise Solutions

Every textbook question below is reproduced verbatim from the NCERT Khel Praveen Unit 2; the answers are original and exam-ready. Practical and observation tasks are given as guided model responses.

Chapter 5 — Understanding Our Body: Exercises

1. In the Preparatory and Middle Stages, you practised different physical activities, including warm-up and cool-down exercises. List five activities that help improve the mobility and function of specific joints.

ANSWER Five joint-mobility activities are: (i) arm circles / shoulder rotations for the shoulder joint; (ii) neck turns and tilts for the cervical (neck) joint; (iii) wrist and ankle rotations for the wrist and ankle joints; (iv) knee bends / lunges for the knee and hip joints; and (v) trunk twists / side bends for the spine. Done gently as part of warm-up, these dynamic movements increase the range of motion, warm the synovial fluid and reduce the risk of joint injury. (Your own correct examples are accepted.)

2. Perform heel raises in both a standing position and a mid-squat position. Try to feel the difference in tension in your calf muscles and identify the muscles involved.

ANSWER In a standing heel raise, the leg is straight and you lift onto your toes; most tension is felt in the upper calf, mainly the gastrocnemius, which acts as you plantar-flex the ankle. In a mid-squat heel raise, the knee is bent, which shortens the gastrocnemius and reduces its pull, so tension shifts lower to the soleus muscle deep beneath it. Both raises also use the Achilles tendon to transmit force to the heel bone. The bent-knee version therefore targets the soleus more, and the straight-knee version the gastrocnemius. (Activity — observe your own muscles.)

3. Observe the movements while kicking and throwing a ball. Identify and list the joints and muscles that contribute to each movement.

ANSWER Kicking a ball: the main joints are the hip (ball-and-socket), knee (hinge) and ankle. The muscles include the quadriceps (knee extension), hamstrings and gluteus (hip movement), and the calf muscles for the ankle. Trunk muscles like the rectus abdominis stabilise the body. Throwing a ball: the main joints are the shoulder (ball-and-socket), elbow (hinge) and wrist. The muscles include the deltoids and pectoralis major (shoulder), biceps and triceps (elbow flexion/extension) and the forearm muscles for the wrist snap. (Observe and record your own actions.)

Chapter 6 — Cardiorespiratory System: Exercises

1. In the Preparatory and Middle stages, you practised different physical activities, including warm-up and cool-down exercises. List five activities that help improve cardiovascular endurance.

ANSWER Five cardiovascular-endurance activities are: (i) running or jogging, (ii) skipping with a rope, (iii) cycling, (iv) swimming and (v) jumping jacks or brisk walking. These keep the heart and lungs working at a raised rate for a sustained period, increasing the heart’s pumping efficiency, lung capacity and the body’s ability to deliver oxygen to working muscles. (Other correct aerobic activities are accepted.)

2. Measure your heart rate while stair climbing and cycling. Compare the changes in heart rate and breathing rate for both activities by creating a chart and recording the differences.

ANSWER Record your resting pulse first, then your pulse and breaths after 2–3 minutes of each activity, in a chart like the one below.

Activity	Heart rate (beats/min)	Breathing rate (breaths/min)
Rest (baseline)	e.g. 72	e.g. 16
Stair climbing	e.g. 130 (higher)	e.g. 30
Cycling	e.g. 120	e.g. 26

Typically stair climbing raises the heart and breathing rate more than gentle cycling because it lifts your whole body weight against gravity and uses large leg muscles intensely. Both raise heart and breathing rate above rest as the body demands more oxygen. (Fill the chart with your own readings.)

3. Do one activity each using your upper body and one using your lower body. Identify and explain the differences in muscle use, tiredness, and heart rate between the two activities.

ANSWER An upper-body activity (e.g. push-ups or throwing) mainly uses the arms, shoulders and chest muscles; an lower-body activity (e.g. squats or running) uses the much larger thigh, hip and calf muscles. Because the lower body contains bigger muscle groups, lower-body activity usually raises the heart rate higher and causes more overall tiredness and breathlessness, as more blood and oxygen are redirected to those large muscles. Upper-body work tires the smaller arm muscles faster locally but raises the heart rate less. (Record your own observations.)

Chapter 7 — Growth, Development, and Maturation: Exercises

1. Explain how biological development, motor skills, and behavioural development help you, giving one example of each.

ANSWER Biological development improves the body’s internal systems — for example, stronger lungs and heart let you run longer without tiring. Motor-skill development improves coordinated movement — for example, learning to dribble a football accurately. Behavioural development improves how you act and feel — for example, controlling your temper and cooperating with teammates during a match.

2. How are heredity and environment responsible for growth?

ANSWER Heredity (genes from parents) sets the basic blueprint — it largely determines potential height, body size and skeletal proportions. Environment decides how far that potential is reached: good nutrition, clean surroundings, healthcare, exercise and emotional support promote full growth, while poor diet, illness, pollution or stress can stunt it. Growth is therefore the result of heredity and environment working together. (Nature and nurture both matter.)

3. Two students of the same age have different heights. Explain the difference in terms of growth and maturation.

ANSWER Children of the same chronological age can be at different stages of maturation. Maturation happens at different rates in different individuals, so one student may have entered a growth spurt and have open, active growth plates, making them taller, while the other’s spurt has not yet begun. Thus the height difference reflects differing biological (maturational) age rather than ability or health. Factors such as heredity, nutrition and hormones also affect each child’s growth. Often the shorter student catches up later when their own growth spurt occurs. (Same age is not the same maturity.)

Chapter 8 — First Aid: Exercises

1. A student fell during a football match and injured their ankle. What immediate First Aid steps should be taken?

ANSWER Apply the PRICE method at once: Protect the ankle (stop play, support it); Rest it without putting weight on it; apply Ice wrapped in cloth for 10–15 minutes; add Compression with an elastic bandage; and Elevate the ankle above heart level to reduce swelling. Stay calm, do not force movement, and if pain or swelling is severe or the player cannot bear weight, seek medical help. (Protection + R.I.C.E.)

2. During a sports event, a player becomes unconscious but is breathing. What should you do?

ANSWER First check for danger and ensure the area is safe. Since the player is breathing normally, place them in the recovery position (on their side) to keep the airway clear and prevent choking. Call for help (dial 112) and continuously monitor breathing until medical help arrives. Do not give CPR while the person is breathing; stay with them, keep them warm and reassured. If breathing stops, begin CPR immediately. (Recovery position + monitor.)

3. What items should be included in a basic First Aid kit?

ANSWER A basic first-aid kit should include: bandages, gauze rolls and pads, an instant cold pack, a thermometer, a first-aid manual, antiseptic wipes, safety pins, tweezers, elastic bandages, adhesive tape, an emergency blanket, gloves, scissors, and emergency/medical contact information for family members.

Check Your Progress — Answer in brief

1. Compare voluntary and involuntary muscles with examples.

ANSWER Voluntary (skeletal) muscles are under our conscious control, attached to bones, striated and used for movement and posture — for example, the biceps and quadriceps. Involuntary muscles work automatically without our control: smooth muscles are non-striated and found in organs like the stomach and blood vessels, and cardiac muscle is found only in the heart wall. We can choose to bend the elbow (voluntary), but we cannot stop our heartbeat or digestion (involuntary).

2. What happens to muscles when you exercise regularly?

ANSWER With regular exercise, muscles increase in size (hypertrophy), strength and endurance. They use oxygen more efficiently, develop more capillaries for better blood supply, store more energy and become less easily fatigued, improving overall posture and performance.

3. What changes occur in breathing and pulse rate when you run compared to when you rest?

ANSWER When running, both breathing rate and pulse rate rise sharply above resting levels. Breathing becomes faster and deeper to take in more oxygen and expel more carbon dioxide, and the heart beats faster to pump oxygen-rich blood to the working muscles. At rest, both return to normal baseline values as the body’s demand for oxygen falls.

4. Design a circuit training to improve cardiorespiratory fitness.

ANSWER A simple circuit of 5–6 stations, performed for 30–45 seconds each with short rests, repeated 2–3 rounds: (1) jumping jacks, (2) high knees / spot jogging, (3) skipping with a rope, (4) mountain climbers, (5) step-ups on a bench, (6) burpees. Begin with a warm-up and finish with a cool-down and stretching. Because the stations keep the heart rate elevated with little rest, the circuit steadily improves heart and lung efficiency and aerobic endurance. (Adjust stations to your fitness level.)

5. “Growth stops after a certain age, but development continues throughout life.” Explain the statement.

ANSWER Growth is a physical, quantitative increase in size, height and weight; once maturity is attained and the growth plates close after puberty, the body stops growing taller. Development is qualitative — it includes learning new skills, improving coordination, gaining knowledge and emotional maturity — and this can keep improving at any age. So a person stops growing in height but can keep developing skills and behaviour throughout life.

6. How can lack of sleep affect growth and development?

ANSWER Much of the body’s growth hormone is released during deep sleep, so insufficient sleep can reduce its secretion and slow physical growth and tissue repair. Lack of sleep also harms development by reducing concentration, memory, learning, mood control and motor performance, and it weakens recovery after exercise.

Check Your Progress — Answer the following in detail

1. Explain how bones and muscles work together to produce movement.

ANSWER Bones form the rigid framework of the body and act as levers, while joints act as the pivots about which these levers turn. Muscles are attached to bones by tendons. When a muscle receives a nerve signal it contracts and shortens, pulling on the tendon and moving the bone at the joint. Muscles work in pairs (antagonists): for example, when bending the elbow the biceps contracts (concentric) while the triceps relaxes; to straighten the elbow the triceps contracts while the biceps relaxes. Ligaments stabilise the joint, cartilage reduces friction, and this coordinated teamwork of bones, joints, muscles and connective tissues produces smooth, controlled movement and force.

2. What happens to muscles when you exercise regularly?

ANSWER Regular exercise causes lasting adaptations in muscle. The muscle fibres grow thicker (hypertrophy), so the muscle increases in size and strength. More capillaries develop, improving the oxygen and nutrient supply, and the muscles store more energy and use oxygen more efficiently, raising endurance. Trained muscles also fatigue more slowly and recover faster, posture and joint stability improve, and the muscles contract more powerfully and with better coordination. Overall, regular training makes muscles bigger, stronger, more enduring and more efficient. (Long-term adaptations.)

3. How does regular physical activity influence growth during adolescence?

ANSWER During adolescence, regular physical activity stimulates bone density, muscle hypertrophy and cardiovascular growth. Weight-bearing exercise strengthens bones, while activity improves motor coordination, strength, flexibility and skill acquisition, enhancing the readiness of the musculoskeletal and neuromuscular systems. It also supports healthy weight, better sleep and hormonal balance, which aid normal growth. However, very heavy vertical load-bearing exercise should be limited in the pre-adolescent stage, as it can affect the epiphyseal growth plates and compromise peak height velocity. Balanced, age-appropriate activity therefore promotes healthy growth and development. (Activity must suit the stage of maturation.)

4. Explain how emotional development changes during teenage years.

ANSWER During the teenage years, hormonal and brain changes make emotions stronger and more changeable, so teenagers may feel intense moods, seek independence and become more self-conscious. They gradually develop the ability to understand and control their feelings, empathise with others and handle stress. Through experiences, friendships and sports, they learn teamwork, patience, handling success and failure, and decision-making. Emotional support from family, teachers and peers helps this transition, building confidence, self-control and a stable identity. Sport in particular teaches discipline and managing emotions during competition. (Emotions mature with experience and support.)

5. Why is it important to stay calm while giving first aid?

ANSWER Staying calm is the first golden rule because panic spreads faster than injury. A calm mind lets you assess the situation clearly, ensure safety, decide the correct steps and act quickly without mistakes. Calmness also reassures the injured person, reduces their shock and fear, and helps you give steady, effective care — whether controlling bleeding, performing CPR or calling for help. A clear, confident first-aider can genuinely save a life, whereas panic wastes precious time. (Calmness saves lives.)

6. Design a simple awareness poster on the importance of first aid in daily life.

ANSWER A poster could carry a bold heading such as “First Aid Saves Lives!” with a simple first-aid box symbol. Include the Three Ps (Preserve Life, Prevent Worsening, Promote Recovery), the PRICE steps for injuries, and the emergency number 112 in large print. Add short slogans like “Stay Calm · Ensure Safety · Call for Help”, a small list of basic kit items, and a reminder that anyone can help in an emergency. Use clear pictures and bright colours so the message is easy to read and remember. (Describe or draw your own design.)

7. Explain how the heart and lungs work together during physical activity.

ANSWER During physical activity, working muscles need more oxygen and produce more carbon dioxide. The lungs respond by breathing faster and deeper to take in more oxygen and remove more carbon dioxide, and oxygen passes into the blood at the alveoli. The heart beats faster and pumps more strongly, increasing cardiac output, so oxygen-rich blood reaches the muscles quickly and carbon-dioxide-rich blood is carried back to the lungs. Through this teamwork of the cardiorespiratory system — lungs oxygenating the blood and the heart circulating it — the body meets the higher energy demand of exercise. (Heart and lungs work as one system.)

8. Why is cardiorespiratory endurance important for overall health?

ANSWER Cardiorespiratory endurance is the ability of the heart, lungs and blood vessels to supply oxygen to the muscles during sustained activity. Good endurance means a stronger, more efficient heart, greater lung capacity and better circulation, so daily tasks and sports can be done without quickly tiring. It lowers the risk of heart disease, obesity and high blood pressure, improves stamina, recovery and energy levels, and supports better mood and sleep. Overall, strong cardiorespiratory fitness is central to lifelong health and well-being. (Endurance underpins overall fitness.)

Extra Practice Questions

Short Answer Type Questions

Q1. Differentiate between anatomy and physiology.

ANSWERAnatomy studies the structure of the body — what parts are and where they are located — while physiology studies function — how those organs and systems work to maintain life.

Q2. Name the three types of muscles and give one feature of each.

ANSWERSkeletal — voluntary, striated, attached to bones; smooth — involuntary, non-striated, in hollow organs; cardiac — only in the heart wall, branched and self-stimulating.

Q3. What is the difference between breathing and respiration?

ANSWERBreathing is the physical act of inhaling oxygen and exhaling carbon dioxide; respiration is the chemical process inside cells where oxygen breaks down glucose to release energy (ATP).

Q4. Define growth, development and maturation in one line each.

ANSWERGrowth = increase in body size (quantitative); development = improvement in skills, function and behaviour (qualitative); maturation = progression of the body towards adulthood and full functional capacity.

Q5. What does R.I.C.E. stand for?

ANSWERRest, Ice, Compression and Elevation — a first-aid method for soft-tissue injuries; with Protection added first it becomes PRICE.

Long Answer Type Questions

Q1. Describe the path of blood through the double circulatory system.

ANSWERIn systemic circulation, the left ventricle pumps oxygen-rich blood through the aorta to arteries, arterioles and capillaries, where tissues take up oxygen and release carbon dioxide. The oxygen-deficient blood returns through venules and veins to the right atrium and right ventricle. In pulmonary circulation, the right ventricle pumps this blood through the pulmonary artery to the lungs, where it loses carbon dioxide and gains oxygen, then returns through the pulmonary veins to the left atrium and left ventricle to be pumped out again. Because blood passes through the heart twice in one circuit, oxygen-rich and oxygen-deficient blood stay separated and tissues receive oxygen efficiently.

Q2. Explain the DRSABCD action plan used in Basic Life Support.

ANSWERD – Danger: ensure the area is safe for yourself, bystanders and the casualty. R – Response: check if the person responds. S – Send for help: call 112 or ask someone to call. A – Airway: open the airway by tilting the head back and lifting the chin, clearing any obstruction. B – Breathing: look, listen and feel for 10 seconds; if breathing normally, use the recovery position, otherwise start CPR. C – CPR: give 30 chest compressions and 2 breaths at 100–120 compressions per minute. D – Defibrillator: attach an AED if available and follow its instructions, continuing until signs of life return or medical help takes over.

MCQs & Assertion–Reason

1. The scientific study of the structure of the human body is called:

(a) physiology (b) anatomy (c) biology (d) pathology

2. Which tissue connects muscle to bone?

(a) ligament (b) cartilage (c) tendon (d) skin

3. The knee is an example of a:

(a) ball-and-socket joint (b) hinge joint (c) pivot joint (d) saddle joint

4. Cardiac muscle is found:

(a) in the limbs (b) in the stomach wall (c) only in the heart wall (d) in blood vessels

5. Energy released during cellular respiration is stored as:

(a) glucose (b) ATP (c) carbon dioxide (d) water

6. The ‘lub’ (S1) heart sound is caused by the closing of the:

(a) aortic and pulmonary valves (b) mitral and tricuspid valves (c) capillaries (d) aorta

7. The average cardiac output of an adult at rest is about:

(a) 1 litre per minute (b) 5 litres per minute (c) 30 litres per minute (d) 50 litres per minute

8. Which process stops after maturity is attained?

(a) development (b) growth (c) learning (d) thinking

9. In the R.I.C.E. principle, ‘C’ stands for:

(a) Calm (b) Care (c) Compression (d) Cooling

10. The three aims (Three Ps) of First Aid are Preserve Life, Prevent Worsening and:

(a) Promote Recovery (b) Provide Medicine (c) Prepare Surgery (d) Protect Property

Answer key: 1-(b), 2-(c), 3-(b), 4-(c), 5-(b), 6-(b), 7-(b), 8-(b), 9-(c), 10-(a).

For each Assertion–Reason question, choose: (A) Both true and the Reason correctly explains the Assertion; (B) Both true but the Reason is not the correct explanation; (C) Assertion true, Reason false; (D) Assertion false, Reason true.

A-R 1. Assertion: Skeletal muscles are called voluntary muscles.

Reason: They are under our conscious control and move body parts as we wish.

A-R 2. Assertion: Breathing rate increases during vigorous exercise.

Reason: The body needs more oxygen for cellular respiration so the muscles can keep working.

A-R 3. Assertion: Growth and maturation occur at exactly the same age in every individual.

Reason: Heredity, nutrition and hormones have no effect on the rate of maturation.

A-R 4. Assertion: An unconscious person who is breathing normally should be placed in the recovery position.

Reason: The recovery position keeps the airway clear and prevents choking while breathing is monitored.

A-R 5. Assertion: One should stay calm while giving first aid.

Reason: Panic spreads faster than injury and a clear mind helps give correct, quick care.

Answer key: 1-(A), 2-(A), 3-(D), 4-(A), 5-(A).

Exam tips for Unit 2

Learn the classifications as lists with one example each — bone types, structural vs functional joints, the three muscle types, and the types of synovial joints. For physiology answers, always link structure to function during exercise (e.g. heart beats faster → more oxygen to muscles). Memorise fixed facts: cardiac output ~5 L/min at rest (up to ~30 L/min in exercise), CPR ratio 30:2 at 100–120/min, and the meanings of RICE/PRICE, the Three Ps and DRSABCD. Use the textbook tables to write neat, point-wise answers.

Common mistakes to avoid

Confusing tendons (muscle-to-bone) with ligaments (bone-to-bone).
Mixing up anatomy (structure) and physiology (function).
Writing that breathing and respiration are the same — respiration is the cellular, chemical process.
Treating growth, development and maturation as identical — growth is quantitative and stops, development is qualitative and lifelong.
Giving CPR to a person who is breathing normally — instead use the recovery position and monitor.
Forgetting to ensure safety / check for danger first before helping an injured person.

Frequently Asked Questions

What chapters are in Class 9 Khel Praveen Unit 2?

Unit 2, Science and Sports, contains four chapters: Chapter 5 Understanding Our Body, Chapter 6 Cardiorespiratory System, Chapter 7 Growth, Development, and Maturation, and Chapter 8 First Aid.

What is the difference between growth, development and maturation?

Growth is a quantitative increase in body size that stops after maturity; development is the qualitative improvement of skills, function and behaviour that continues throughout life; maturation is the body’s progression towards adulthood and full functional capacity, with different systems maturing at different times.

What does PRICE stand for in first aid?

PRICE stands for Protection, Rest, Ice, Compression and Elevation. It improves on the basic R.I.C.E. method by adding Protection first, and is used for soft-tissue injuries such as a twisted ankle.

Note: All textbook exercise questions are reproduced verbatim from the NCERT Khel Praveen (Class 9 Physical Education & Well-being) Unit 2; all answers, notes, key terms, MCQs and A–R items are original and expert-checked for the 2026–27 session.

« Unit 1 Khel Praveen (all units) Class 9 Physical Education Unit 3 »